A-A+
According to paragraph 2 how did birds adapt
问题详情
According to paragraph 2, how did birds adapt to achieve efficient flight?
A.They developed a skeleton with fewer bones.
B.Their organs became smaller over time.
C.Most of their weight was distributed in their heads.
D.Teeth were replaced by a beak made of keratin.请帮忙给出正确答案和分析,谢谢!
参考答案
正确答案:D
解析:... birds are toothless, an adaptation that trims the weight of the head... The bird's beak, made of keratin, has proven to be very adaptable." Choice A is not correct because the skeleton is honeycombed, which makes it strong and light, but it does not have fewer bones. Choice B is not correct because the organs are fewer, not smaller. Choice C is not correct because the head is lighter, not heavier.